Lovato DCTLA4000150 Thyristor Module

A 15 kvar thyristor switch for fast capacitor steps

The DCTLA4000150 is a thyristor module from Lovato Electric that switches one capacitor step electronically. Its step power is 15 kvar at 400 VAC with rated current Ie of 22 A, operating voltage range 340-440 V, and 2 controlled phases with a peak inverse voltage of 1800 VAC.

Because a thyristor switches at the zero-voltage crossing, there is no contactor wear and no inrush transient, so steps can be switched many times per minute. It is intended for fast (dynamic) power-factor correction banks driven by a controller such as the DCRG8F.

Technical specifications

Selecting the module

Choose the module from the capacitor step it will switch (here 15 kvar at 400 V) and from the system voltage: the family includes 400 V, 480 V and 690 V modules from 7.5 to 100 kvar. A module rated for 400 V must not be used on a 480 V or 690 V system.

The datasheet lists a fan supply output for one built-in fan of type EXP8004, so check the heat dissipation and cooling requirement for continuous duty before finalising the panel layout.

Applications and installation

Typical uses are welding plants, crane and hoist drives, presses, wind and solar auxiliaries and any plant with rapidly changing reactive power. The module is wired in series with the capacitor and a detuning reactor where harmonics are present.

Control input options: 12-24 VDC input or free-voltage input, or the serial port with an optional card. A relay output gives a fault signal, and an NTC probe input monitors heatsink temperature.

Control options for the DCTL module

Lovato’s data sheet lists three ways to command the DCTLA4000150. It can be driven by a 12 to 24 V DC input signal (operating range 8 to 30 V DC), by a free-voltage input, or through the RS485 serial port when the optional card EXC1042 is used together with a DCRG8F power factor controller and the EXP1012 module. This makes the module suitable both for simple panels with a static output controller and for systems where the controller manages the steps over a serial link.

The module needs an auxiliary supply of 100 to 240 V AC, 50/60 Hz, with a maximum power consumption of 11.8 VA. Maximum power dissipation is 4.6 W. The two controlled phases switch the capacitor bank, and the peak inverse voltage rating is 1,800 V AC.

Monitoring and protection connections

• NTC probe input: for an NTC temperature sensor (Lovato ordering code NTC01), measuring range −25 to +85 °C, maximum connection length 3 m.
• Fan output: one built-in fan type EXP8004, supplied at 5 V DC by the module.
• Digital input C-IN1: 5 V DC internal contact voltage, input current up to 10 mA, signal delay at least 50 ms.
• Relay output: one changeover (SPDT) contact; NO contact AC1 5 A at 250 V AC or 5 A at 30 V DC, NC contact 3 A; UL/CSA and IEC/EN 60947-5-1 designation D300; mechanical life 10 million cycles.

Wiring the power terminals

Power connections use fixed double-lock clamp terminals taking conductors from 2 × 2.5 mm² to 2 × 35 mm² (2 × AWG 18 to 2 × AWG 2), tightened to 4 to 5 Nm. The relay output uses screw terminals for 0.2 to 4 mm² at 0.8 Nm, and the fan and digital input terminals take 0.2 to 2.5 mm². The rated insulation voltage is 480 V and the rated impulse withstand voltage is 4 kV.

Documents and quotation

All data on this page for DCTLA4000150 is taken from the Lovato Electric catalogue datasheet (English), which you can download from the attachment list. Please confirm the capacitor step size, the system voltage, the cooling arrangement and the controller that will drive the module before you order, and note that the manufacturer may revise datasheet values. Related items are listed under power modules. To request DCTLA4000150, send the quantity and delivery location with the quotation form; Seven Star LLC is an independent supplier based in Muscat.